使用模板匹配的方法对屏幕视频进行编码时，视频图像中近80%像素点残差为零。为了更好地对非零残差点进行编码，进一步提高编码效率，提出基于模板匹配的调色板方法。该方法利用非零残差点的统计信息，生成全局的和局部的调色板，使用调色板索引重新对非零残差点进行编码，进一步缩小预测残差。实验结果表明，采用文中方法对非零残差进行修正，最多可提升30%的编码效率。%With the development of wireless network and hand-hold devices such as iPad, personal digital assis-tant and smartphone, screen content video becomes more popular for screen sharing or screen broadcasting. In our previous work, we proposed a pixel granularity template matching prediction method; almost 80% residual samples are zero for some screen content picture, and other 20% non-zero prediction residuals are encoded with the intuitive method. In order to further improve the coding efficiency, a palette based method is proposed in this paper. During encoding, a global palette and a local palette will be derived according to the statistics of non-zero residuals. Non-zero residuals will be encoded with the palette index. Palettes, indices and residuals will be trans-mitted. The experiment results show that the proposed palette tool can greatly improve the coding efficiency.
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